In the year of l981 to l982, the structural study of non-primate EBV-like virus DNA will be further continued. A cell line which produces an orangutan virus is now available and the physical map of this virus DNA will be determined. Homology among the three viral DNA, EBF, HVP and orangutan will be determined by DNA DNA reassociation kinetics and hydroxyapatite column chromatography. A similar study will be conducted for the internal repeat sequences which are known to exist in the three viral DNAs. The possibility of the inhibition of RNA processing has been suggested as a mechanism of noninducibility of some EBV genome-carrying cells. Thus this possibility will be examined by Berk and Sharp analysis for Raji cells with and without induction of IUDR. B95 productive cells as well as Putko and Dutko cells will also be examined. Viral DNA integration into host cell DNA will be studied by Southern blot hybridization which now can detect one EBV genome per cell without any difficulty.